Is http-proxy-middleware 4.1 vulnerable?

npm · 2 releases from 4.1.0 to 4.1.1 · latest http-proxy-middleware is 4.2.1 · checked 1 Nov 2026

No known advisories in the last release

http-proxy-middleware 4.1.1, the last 4.1 release, has no known advisories. 1 advisory affects earlier 4.1.x releases, so update to 4.1.1.

Update within 4.1:npm install http-proxy-middleware@4.1.1

Is your project affected?

Private repo? Upload its lockfile instead, or connect GitHub to check every repo.

Fixed within 4.1.x, affecting earlier releases

  • HighCVE-2026-55603GHSA-gcq2-9pq2-cxqm18 Jun 2026

    http-proxy-middleware: multipart/form-data field injection via unescaped CRLF in `fixRequestBody`

    Affected
    >=3.0.4 <3.0.7 · >=4.0.0 <4.1.1
    Fixed in
    3.0.7, 4.1.1

Which of your client projects are still on http-proxy-middleware 4.1?

NPMscan reads the lockfiles in every GitHub repo you pick, finds the exact http-proxy-middleware version each one installs, and checks it against these advisories. Each finding comes with the command that fixes it.

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Other http-proxy-middleware versions

Advisory data from OSV.dev (opens OSV.dev in a new tab), which includes the GitHub Advisory Database. Release list from the npm registry. Refreshed daily.